Add IntelliJ files to .gitignore

Change-Id: I45dd03d4295322ecc0f10c4673848c1fe85d5e98
Issue-ID: POLICY-509
Signed-off-by: Alexis de Talhouët <adetalhouet89@gmail.com>
diff --git a/.gitignore b/.gitignore
index 24ec484..d2e6a3b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,7 @@
 .metadata/
 /bin/
 controlloop/templates/template.demo/src/test/resources/xacml/autogenerated_*.xml
+
+# IntelliJ file
+.idea
+**/*.iml